搅拌摩擦加工超细晶及纳米结构Cu-Al合金的微观组织和力学性能研究.pdf

《搅拌摩擦加工超细晶及纳米结构Cu-Al合金的微观组织和力学性能研究.pdf》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、第50卷第2期金属学级、厂o1．50NO．22014年2月第245-251ACTAMETALLURGICASINICAFeb．2014PP．245—251搅拌摩擦加工超细晶及纳米结构Cu．AI合金的微观组织和力学性能研究薛鹏肖伯律马宗义(中国科学院金属研究所沈阳材料科学国家(联合)实验室，沈阳110016)摘要通过强制冷却的搅拌摩擦~I(FSP)技术在cu—Al合金中得到了超细晶和纳米结构的微观组织，利用电子背散射衍射、透射电子显微镜等技术研究了层错能对FSPCu．A1合金微观组织和力学性能的影响．结果表明，FSPCu．A1合金为均匀、等轴的再结晶组织，随着层错能的减小，晶粒尺寸不断降低

2、，而且在低层错能的FSPCu．A1合金中，超细晶粒内部生成了丰富的纳米孪晶片层组织，进一步细化了微观组织．由于微观组织的逐步细化，FSPCu—A1合金的强度随层错能的降低逐步提高，而均匀延伸率呈现出先增加后减小的趋势．关键词搅拌摩擦加工，Cu．AI合金，层错能，纳米孪晶片层，力学性能中图法分类号TG172文献标识码A文章编号0412—1961(2014)02—0245—07MICRoSTRUCTUREANDMECHANICALPRoPERTIESoFFIUCTIoNSTIRPRoCESSEDULTRAFINE．GRAINEDANDNANoSTRUCTUREDCu．AlALLoYSXUEP

3、eng,XIA0Bolii,MAZongyiShenyangNationalLaboratoryforMaterialsScience，InstituteofMetalResearch，ChineseAcademyofSciences，Shenyang110016Correspondent．"MAZongyi,professor,Tel：(o24)83978908,E-maihzyma@imrac．cnSupportedbyNationalNaturalScienceFoundationofChina0s．51071150,51301178and51331008)Manuscriptre

4、ceived2013—10—18，inrevisedform2013—12—24ABSTRACTUltrafine—grained(UFG)andnanostructured(NS)materialshaveattractedconsiderableinterestduetotheirspecialmicrostructureandmechanicalproperties．Severeplasticdeformationisoneoftheoptimum印-proachestofabricatebulk，denseandcontamination—freeUFGandNSmetallic

5、materials．However,highdensityofdislocationsandunstablemicrostructurewereusuallyinducedintheseUFGandNSmetallicmaterials，resultinginpoortensileplasticityandfatigueproperties．Inthisstudy,bulkUFGandNSCu—A1alloysweresuccessfullypre—paredviafrictionstirprocessing(FSP)withadditionalforcedwatercooling．FS

6、PCu-A1alloysexhibiteduniformrecrystallizedmicrostructurewithequiaxedultrafinegrains，andthegrainsizesreducedgraduallyasthestackingfaultenergy(SFE)decreased．Abundantnano-twinlayersformedintheultrafinegrainsofFSPCu—A1alloyswithlowSFEs，whichfurtherrefinedtheultrafinegrainsandNSmicrostructurewasachiev

7、ed．ThestrengthoftheFSPCu—A1alloysincreasedclearlywithdecreasingtheSFEsduetothegraduallyrefinedmicrostructure，buttheuni—formelongationincreasedinitiallyandthendecreasedintheCu-A1alloywiththelowestSFE．KEYWoRDSfrictionsti